Answer
$\dfrac{130000}{999}$
Work Step by Step
Here, we have $a_n= a_1 r^{n-1}$ for the Geometric series.
Re-arrange the given series as: $130.130130...=130 +0.130 (0.001) +130(0.001)^2 +....$
First term $a_1=130$ and Common ratio $r=0.001$
The sum of an infinite Geometric Series can be found using: $S_n=\dfrac{a_1}{1-r}$
Thus, $S_n=\dfrac{130}{1-0.001}$
Hence, $S_n=\dfrac{130000}{999}$